Purple "Pimpleback" Shell 8mm Faceted Coin Bead - 15-16 Inch 20x22-28x34mm unique iridescent patinas (caused by

unique iridescent patinas (caused by centuries of burial)

Azurite is a Copper carbonate mineral that forms in masses

Libyan Desert glass- Found in the eastern Sahara desert

A variety of Andalusite

Purple "Pimpleback" Shell 8mm Faceted Coin Bead - 15-16 Inch 20x22-28x34mm unique iridescent patinas (caused byA "pimpleback" is a freshwater mussel (Cyclonaias pustulosa) common in North American rivers, characterized by a thick, yellow brown to brown shell covered in bumps (pustules). While not typically purple, the inner lining (nacre) can be iridescent, and related species in the pimpleback complex are sometimes found in Texas waters.